<s>
Ethernet	O
routing	O
switch	O
4000	O
series	O
or	O
(	O
ERS	O
4000	O
)	O
in	O
computer	B-Architecture
networking	I-Architecture
terms	O
are	O
stackable	B-Protocol
layer-3	B-Application
(	O
routers	B-Protocol
)	O
and	O
layer-2	B-Protocol
(	O
switches	B-Protocol
)	O
designed	O
and	O
manufactured	O
by	O
Avaya	O
for	O
Ethernet	O
devices	O
.	O
</s>
<s>
The	O
switches	B-Protocol
are	O
1U	O
high	O
and	O
five	O
models	O
were	O
originally	O
available	O
which	O
consisted	O
of	O
the	O
;	O
4526FX	O
,	O
4550T	O
,	O
4550T-PWR	O
,	O
4548GT	O
and	O
4548GT-PWR	O
.	O
</s>
